JPH0362435A - Thin film formation device - Google Patents

Abstract

PURPOSE:To ensure the high rate formation of a film and improve film quality by combining and using concurrently RF plasma arc and arc plasma. CONSTITUTION:A substrate 3 for forming a film thereon is housed in a vacuum reservoir 1, and gas introduced through a gas introduction tube 9 is changed into RF plasma. Concurrently, the gas is activated with arc plasma and a thin film of good quality is formed on the substrate 3 at a high rate. The RF plasma is generated with an RF coil actuated with an RF power supply 7. The arc plasma is generated with an arcing electrode 4 actuated with a DC power supply 8. The substrate 3 is placed on a substrate holder 2 and heated up to the predetermined temperature with a heater 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for forming high-quality thin films.

[Prior Art] Conventionally, the CVD method in which a gas is introduced and reactants of the gas activated by arc plasma and reactants of the gas activated by RF plasma are individually deposited on a substrate is already well known. It is being

[Problem to be solved by the invention]

By the way, with arc plasma alone, ionization in the gas is low and the amount of radicals is also low, so a sufficient deposition rate cannot be obtained unless the pressure in the chamber is increased to increase the amount of radicals. However, if this is done, the distance between the electrode and the substrate must be made quite close, making it susceptible to the influence of the electrode. On the other hand, with only RF plasma, the ionization of the gas is not so high, and the amount of radicals is not so large.

An object of the present invention is to provide an apparatus capable of forming a high-quality thin film at high speed by generating RF plasma and simultaneously promoting activation of gas by arc plasma.

[Means to solve the problem]

In order to achieve the above object, the thin film forming apparatus according to the present invention includes a vacuum chamber incorporating a substrate holder for mounting a substrate, an RF coil for generating RF plasma outside the vacuum chamber, and generating arc plasma. and an arc generating electrode that activates reaction products in the RF plasma acting on the substrate.

[Function] In the present invention, products reacted by ions and electrons in the RF plasma generated through the coil electrode installed outside the vacuum chamber are transferred to the products generated by the arc electrode installed below the RF plasma. Since activation can be further enhanced by plasma, thin films can be formed with high quality and at high speed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a quartz tube 10 is attached to the upper part of a vacuum chamber l having a degassing port 13. There is a heater 1 in the vacuum chamber l.
A substrate holder 2 containing the quartz tube 10 is installed.
The board 3 is mounted facing the board 3. 1
2 is an AC power source for heating the heater l'l. An arc electrode 4 for generating arc plasma is installed directly above the substrate holder 2, facing the quartz tube 10. 8 is an arc electrode.

On the other hand, an RF coil 5 for generating RF plasma is installed in the quartz tube 10 communicating with the vacuum chamber 1. Reference numeral 7 denotes an RF power source that energizes the RF coil 5. A gas introduction pipe 9 having a valve 6 is connected to the quartz tube 10 .

A case in which a diamond thin film is formed using this apparatus will be specifically described as an example.

First, using a diffusion pump or a turbo pump and an oil rotary pump, the inside of the vacuum chamber 1 is evacuated to a temperature below 1×10-” Torr by degassing from the degassing port 13. The substrate temperature is set to about 500°C.
Next, open the valve 6 to introduce gas, introduce high-purity H yogas and hydrocarbon gas or organic compound gas, and set the vacuum degree of the metal body in the vacuum chamber to 1OTorr.
Set to a certain degree. Further, the distance between the arc electrode 4 and the substrate 3 is set to about 1 cm, and in this state, the coil 5 is
~100OW RFI! A force is applied to cause discharge, and at the same time, a current of several tens of volts and about IOA is passed through the arc electrode 4 to generate arc plasma and grow a film on the substrate 3.

In this example, film formation was performed in this state for about 10 minutes. The thickness of the diamond film formed in this way is approximately 10
It was pm. When the film was measured by Raman spectroscopy, a sharp peak was obtained only at 1330 cm-'.

In addition, the Vickers hardness of this film was measured and was approximately 12.
A value of 000 was obtained. This value is the same as that of natural diamond. Furthermore, when the thermal conductivity of the thin film was measured, a value of about 200 W/Kcm was obtained. This is the same as high-pressure synthesized diamond. Thus, it can be seen that a high quality diamond thin film can be obtained at low temperatures according to the present invention.

[Effects of the Invention] As described above, the present invention combines RF plasma and arc plasma to enhance the activation of gas, so that a high-quality thin film can be formed at a relatively low temperature. Note that a high-quality diamond film can be obtained similarly even if a bias is applied between the arc electrode and the substrate.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a thin film forming apparatus according to an embodiment of the present invention. l...Vacuum chamber 2...Substrate holder 3...
・Substrate 4, 8... Arc electrode 5...
・RF coil 6...Valve 7...RF power supply lO...Quartz tube 12...AC power supply

Claims (1)

[Claims] (1) A vacuum chamber with a built-in substrate holder for mounting the substrate,
an RF coil that generates RF plasma outside the vacuum chamber;
said R for generating arc plasma and acting on said substrate;
A thin film forming apparatus characterized by having an arc generating electrode that activates reaction products in F plasma.